Cattle for conservation? How do wild grazers respond to cattle grazing on shared rangelands in East Africa
Forty percent of earth’s land surface is used for grazing domestic animals. These lands also support many wild large mammals and are vital to their continued existence. Consequently, conservation efforts are increasingly aimed at managing land for wildlife-livestock coexistence. In East Africa, many ranches and conservancies have now adopted integrated systems of cattle production and wildlife tourism. However, there are still many unanswered questions about how species will respond in these systems. I investigated how body size and digestion affect responses of a range of wild grazers to cattle grazing, focusing on three ruminants (Thomson’s gazelle, hartebeest, buffalo) and two non-ruminants (warthog, plains zebra) spanning a range of body sizes. Detailed spatial data on cattle use intensity was obtained using GPS collars on cattle herds. I then examined the impact of cattle on vegetation, and in turn on movement and behavior of wild grazers.
Results show that cattle change both the quantity and quality of grass, and may improve vegetation for some species. Small species preferred low biomass areas grazed more by cattle, while buffalo were found mostly in high biomass areas away from cattle. When grass is not limiting, zebra are also drawn to areas of high cattle use after rain. Non-ruminant species were more evenly distributed and utilized more of the available habitats than their similar-sized ruminant counterparts. Understanding the effect of cattle on different species will allow ranchers to adjust management plans to promote coexistence, supporting both human livelihoods and wildlife conservation. Cattle may even be used as a tool to manage rangelands for wildlife.